Specular reflection means the reflection on some in the form of a beam of light but not scattered. In this reflection unless the eye is placed in the path of the reflected beam the viewer is unaware of the existence of light. Diffuse reflection means the reflection of light energy in the scattered form in all direction. In this reflection the viewer can see the illuminated surface but not the light source.
Glare means the brightness within the field of vision of such a character as to cause annoyance, discomfort, interference with vision or eye fatigue.
A polar curve is a convenient way of showing how the candle power of a lamp varies in different directions. Polar curves are used to determine the M.H.C.P.,M.S.C.P. and the actual illumination of a surface by employing the candle power in the particular direction.
Due to its unsymmetrical shape.
Hard and long shadows are avoided by(a) using large numbers of small luminaires mounted over a minimum height of 2.5 metres, (2) using wide surface sources of light by using diffusing globe over filament lamp or by using indirect lighting system.
The flux emitted per unit area of the source in a direction at right angles to the surface is known as brightness. Its unit is
It is the ratio of illumination under normal condition of old installation to the illumination under ideal condition of new installation.
Multiple Choice Question (MCQ) of Materials page-6:51. The permeability and permittivity of a medium are
Multiple Choice Question (MCQ) of Materials page-5:41. Bakelite is
Multiple Choice Question (MCQ) of Materials page-4:31. Which of the following pairs is commonly used in thermocouples?